Water treatment systems, particularly swimming pool chlorinators, often employ chemical tablets that slowly dissolve while partially immersed in a flow of water. The chamber enclosing and supporting the tablet should be constructed so that the tablet dissolves completely and at a controllable rate.
U.S. Pat. No. 5,743,287, which issued to George P. Rauchwerger on Apr. 28, 1998, is directed to a swimming pool chlorinator that has a flow pipe that is removably attached to the inlet jet pipe from the pool circulation system and a container for chlorine-containing tablets that is located above the flow pipe. The chlorinator is submerged and the container has an opening to allow water from the pool to flow into the container and dissolve the tablets. A duct from the bottom of the container leads to the interior of the flow pipe. The duct extends into the flow pipe to constrict the flow through the pipe, so that this flow causes chlorinated solution to be aspirated from the container into the flow by means of the Venturi effect. The container is transparent so that the chlorine tablets are visible from outside the container. The container further has a removable lid for refilling the container. The container opening comprises a slotted hole in the lid, with a sliding plate that can be moved over this slot to vary the size of the opening and thereby regulate the flow through the container. The flow pipe has a knurled end that is inserted in the inlet jet pipe, so that the inlet jet pipe supports the chlorinator and the entire assembly may be removed from the pool for refilling.
U.S. Pat. No. 6,221,244, which issued to Ihssan F. Yassin on Apr. 24, 2001, is directed to a swimming pool chlorinator that utilizes a cylindrical housing that has an internal chamber. Within the internal chamber is concentrically mounted in a close fitting manner a valve member. The sidewall of the housing has a series of elongated slits and also the valve member has a series of similar elongated slits. The housing has mounted thereon at least one suction cup with the suction cup to be securable to a swimming pool wall surface or other surfaces associated with a swimming pool and beneath the surface of the water in the pool. Within the internal chamber of the housing is located one or more chlorine tablets. The valve member is to be adjusted relative to the housing so that the slits of the housing are unrestricted permitting free flow of water through the housing or the slits are restricted partially thereby limiting the amount of flow of water through the internal chamber. As the water is conducted through the internal chamber, the chlorine tablet is dissolved within the water, which chlorinates the water of the swimming pool when this water is conducted exteriorly of the housing.
U.S. Pat. No. 6,337,024, which issued to Carl L. Hammonds on Jan. 8, 2002, is directed to an apparatus and method for dissolving chemical tablets for creating a variable rate of chemical dissolution in a stream of constant flow rate of untreated liquid, especially water. The apparatus includes a housing in which a container is placed. The container includes a sieve plate or perforated grid, which separates the container into an upper chamber in which chemical tablets are stored and a lower mixing chamber. A collection reservoir is defined in an annular outside the container wall and inside of the housing. Several arrangements are illustrated by which a vortex of liquid is generated of controllable variable intensity in the lower or mixing chamber thereby creating uneven liquid pressure beneath the perforated grid as a function of radial distance. As a result, fluid passes aggressively through outer radial perforations or holes in the grid that impinge on the chemical tablets stacked on the grid. The liquid circulates in the upper chamber from the outward radial position toward the center of the grid plate, while eroding the tablets, and returns to the mixing chamber. A portion of the liquid exits into the collection reservoir. Liquid communication also exits from a hole in the bottom of the lower mixing chamber, which is open to the collection reservoir. Varying the intensity of the vortex varies the rate of chemical dissolution, yet the flow rate of liquid through the apparatus is constant.
U.S. Pat. No. 6,413,416, which issued to Leon Buchan on Jul. 2, 2002, is directed to a water treatment apparatus including a water treatment vessel providing a water treatment zone, which, in use, will contain a volume of water to be treated. A water inlet leads into the vessel, with a water outlet leading from the vessel. A cartridge holder for holding a water treatment cartridge containing a water treatment substance for treating water in the vessel, and a controller for controlling the level of water in the vessel, are also provided.